Coffee machine



FIG. 1 is a left side, front and top view of the coffee machine embodying my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a rear view thereof. 

The ornamental design of a coffee machine, as shown and described. 